In recent years, the semiconductor integrated circuit elements (IC chips) used for a CPU in a computer or the like operate at higher speeds, and with higher level functional features, than previously. Along with this advance, the number of terminals has increased and the terminal interval has tended to be smaller and narrower. Generally speaking, terminals in large numbers are densely packed on the bottom surface of the IC chip in an array, and a terminal block so formed is connected to a terminal block at the motherboard side by a “flip chip” connection. However, because there is a large difference in pitch between the terminal block at the IC chip side and the terminal block at the motherboard side, it is difficult to directly connect the IC chip to the motherboard. Therefore, the connection method generally employed is one wherein a package constituted by the IC chip, which is mounted on a wiring board for mounting the IC chip, is produced and then mounted on the motherboard. Examples of such wiring boards which constitute this type of package include a wiring board wherein a capacitor is embedded in a core substrate so as to attain a reduction in switching noise of an IC chip and a stabilization of power supply voltage. Since a length of the wiring connecting an IC chip and a capacitor becomes long, the above effect cannot be obtained due to an increase in inductance component of the wiring whereby the capacitor is preferably disposed near the IC chip. There has been suggested, as an example, a circuit board in which a capacitor is embedded in a core disposed directly under an IC chip. For example, see Japanese Patent Application Laid-Open (kokai) No. 2005-39243 (refer to FIG. 4, etc.).
When a power supply voltage supplied to an IC chip is not sufficient, it will cause a malfunction of the IC chip. Thus, there has been a demand for supplying as much electrical power to the IC chip as possible. A conventional wiring board provides a plurality of power supply pathways used for supplying the electrical power to the IC chip. Such a power supply pathway includes a first power supply pathway connected to the IC chip through a through-hole conductor which penetrates a core board in a thickness direction and a second power supply pathway connected to the IC chip through a via conductor which is provided in a capacitor.
For example, the conventional wiring board for mounting an IC chip is manufactured in the following procedures. First, a core board made of polymer material and including an accommodation hole which opens at both of a core main surface and a core rear surface is prepared. In addition, an embedding capacitor which includes a plurality of electrodes on a capacitor main surface and a capacitor rear surface, respectively, is prepared. Next, an opening portion at the core board rear surface side of the accommodation hole is scaled by an adhesive tape or the like, and, in this state, the embedding capacitor is accommodated in the accommodation hole and temporarily fixed therein. In a subsequent fixing step, a resin filler is filled in a gap between an inner face of the accommodation hole and a side face of the capacitor and hardened to fix the capacitor to the core board. Then, resin insulating resin insulating layers made of polymer material as a main component and conductor layers are formed on a top surface and a rear surface of a compound base material composed of the core board and the capacitor. As a result, a predetermined wiring board is produced. It is noted that a wiring board having the plurality of capacitors, which are disposed in the accommodation holes in the lateral direction, in which a part of the electrodes in the capacitor and the conductor patterns on the core main surface are connected through connecting conductors, has been disclosed. However, there is a problem that a connecting conductor is only connectable to an electrode disposed on an outer circumference portion of the capacitor.